need to make a change or correct an error on your federal income tax return after you e-filed or mailed it? you can or may need to amend your return. perhaps you are eligible for a deduction or credit and you missed it the first time. revising a tax return is done by filing an amendment. you need to use form 1040x to correct a previously filed form 1040, form 1040a, form 1040ez, form 1040nr or form 1040nr-ez plus any other necessary schedules and forms. also, amended tax returns cannot be e-filed, they must be mailed to the irs on paper for manual processing. processing time for an amended return generally runs about 8 to 12 weeks, but sometimes longer during the busy season. should i file an amendment? you should file an amended tax return if you need to correct information that will alter your tax calculations. you can use an amended return to make corrections to your filing status, dependents, income, deductions, or tax credits. for example, if you need to report additional income from a w-2 that arrived after you filed your original return, you'll need to file an amendment. similarly, if you need to remove dependents because you were not eligible to claim them, you should file an amendment. you don't need to file an amended return if you are only correcting math errors as the irs computers will check your math and correct any errors in calculation. math errors are errors in adding or subtracting items on your tax return. will the corrected information result in an additional refund? keep in mind there's a three-year statute of limitations on issuing tax refund checks. this three-year period is measured from the date you filed your original tax return. if you filed your return before april 15th, the three-year period begins from april 15th. if you requested an extension, the three-year period runs from october 15th (internal revenue code section 6511(b)(2)(a)). if this three-year period has passed, you can only receive refunds for overpaid taxes that were actually paid during the previous two years. reasons to file an amendment: • claim additional dependents • remove dependents you previously claimed • report your proper filing status • report additional income from a w2, 1099, or other income statement • make changes in your above-the-line deductions, standard deduction or itemized deductions • change your personal exemptions • claim additional tax credits, removing tax credits mistakenly taken, or recalculating the amount of the credits • report additional withholding from a w-2 or 1099 here are eight key points the irs wants you to know about when considering whether to file an amended federal income tax return. 1. use form 1040x, amended u.s. individual income tax return, to file an amended income tax return. 2. use form 1040x to correct previously filed forms 1040, 1040a or 1040ez. an amended return cannot be e-filed; you must file it by paper. 3. generally, you do not need to file an amended return to correct math errors. the irs will automatically make that correction. also, do not file an amended return because you forgot to attach tax forms such as w-2s or schedules. the irs normally will send a request asking for those. 4. be sure to enter the year of the return you are amending at the top of form 1040x. generally, you must file form 1040x within three years from the date you filed your original return or within two years from the date you paid the tax, whichever is later. 5. if you are amending more than one tax return, prepare a 1040x for each return and mail them in separate envelopes to the appropriate irs campus. the 1040x instructions list the addresses for the campuses. 6. if the changes involve another schedule or form, you must attach that schedule or form to the amended return. 7. if you are filing to claim an additional refund, wait until you have received your original refund before filing form 1040x. you may cash that check while waiting for any additional refund. 8. if you owe additional 2012 tax, file form 1040x and pay the tax before the due date to limit interest and penalty charges that could accrue on your account. interest is charged on any tax not paid by the due date of the original return, without regard to extensions. for additional information about filing an amendment, see irs topic 308. note: your state tax liability may be affected by a change made on your federal return. for information on how to correct your state tax return, contact your state tax agency. file your taxes online with taxbrain! with taxbrain, you can get all the free technical support you need to prepare your own taxes. get your free account now, visit taxbrain.com.